If presented with a German court order. Should they rather act against the law? Be a safe haven for criminals?

I prefer that they stick to the law and build a great service that does everything possible to stop illegal intrusion (data mining, secret service spying). It's way better than most email services, criticizing them for sticking to the law is nitpicking.

Building an encrypted calendar is at the top of our to-do list right now as we desperately need a solution to schedule and share calendar entries securely ourselves. However, first, we have to finish the new client to push it our of beta and update the Tutanota Android and iOS apps so that you can use your encrypted mailbox with very good speeds and many more features on all your devices. Once we are done with that, we will build the encrypted calendar.